(a) Field
Embodiments of the present invention relate to a pouch and a rechargeable battery, and a manufacturing method thereof.
(b) Description of Related Art
Rechargeable batteries can be discharged and recharged, unlike primary batteries, which are not designed to be recharged. Small capacity rechargeable batteries are used for small portable electronic devices such as mobile phones, laptop computers, and camcorders, while large capacity batteries are widely used as power sources for driving motors of hybrid vehicles, etc.
The rechargeable battery includes an electrode assembly made of a positive electrode, a negative electrode, and a separator and a case receiving it, and may be classified into a cylindrical type, a prismatic type, a pouch type, etc., according to a shape thereof. Among them, the pouch type rechargeable battery may be easily formed into various exterior shapes and has a small weight such that the pouch may be made of a laminate sheet that is generally used as the exterior of a lithium-ion rechargeable battery.
The pouch forming an exterior made of the laminate sheet may be formed with a press. For example, the laminate sheet is placed on a mold, and then the laminate sheet is pressed by a punch and is elongated (e.g., stretched) to form the pouch.
Here, the corner portion of the pouch contacting the edge portion of the punch while the laminate sheet is elongated (e.g., stretched) is thinner than the remaining portion. As described above, if the laminate sheet is thin when forming the pouch, it is difficult to ensure durability such that it is difficult to ensure the safety of the electrode assembly received in the pouch.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.